Electromagnet construction.



H. E. REEVE.

ELE CTROMAGNET CONSTRUCTION.

APPLICATION FILED APILB, I911.

Patented Aug. 7, 1917.

INVENTOR WITNESSES IUNIITED STATES PATENT OFFICE.

HENRY E. REEVE, OF NEW YORK, N. Y.

ELECTROMAGNET CONSTRUCTION.

Specification of Letters Patent.

Patented Aug. '7, 1917.

Original application filed December 1, 1910, Serial No. 595,042. Dividedand this application filed April 8,

To all whom it may concern:

Be it known that I, HENRY E. REEVE, a citizen of the United States, andresident of New York, in the county of Kings and State of New York, haveinvented certain new and useful Improvements in ElectromagnetConstruction, of which the following is a specification.-

It has been customary to form the heads of 'electromagnets of fiber orhard rubber. Fiber is absorbent and therefore objectionable. Hard rubberis very fragile and is injured by heat. Difliculty has been encounteredin such constructions, particularly when the coil is immersed in aheated liquid for the purpose of applying a protective coating. The heatif excessive is likely to soften and warp the rubber heads and loosenthem from the magnet cores. Similarly the heads are injured if themagnets are sub-v jected to heat when in use. The principal object of myinvention is to form an electromagnet with heads which can be readilyput on the core but which will be compact and inexpensive and notinjured by heat and which will be durable and permanent and unaffectedby moisture and not liable to chemical injury.

The invention contemplates forming each head of the magnet of a washeror disk of suitable metal preferably such as brass and having a centralopening to receive the core. Parts of the metallic disk are cut away soas to make the head somewhat flexible for the purpose of assembling. Themethod of securing the head on a grooved core is also an important partof my invention. A layer of mica or other suitable insulating materialis preferably interposed at the inner surface of the metallic.v head.

Figure 1, shows an electromagnet of horseshoe type, the coil windingsbeing omitted from one of the cores.

Fig. 2, is a perspective view of'the parts of a magnet embodying theimprovements of my invention.

Fig. 3, is an end view of a single coil magnet.

Fig. 4, is a detail side view showing one end of the magnet and the headin section.

Fig. 5, is an end view of the head of a mIOdified construction.

Fig. 6, is another modified form of head Serial No. 619,665.

Fig. 7, is an end view of a core for the disk of Fig. 6.

In Fig. l the two cores 1 and 2 are connected by the bar 3. Core 1 has awinding 4. The outline of a winding for core 2 is indicated by thedotted line 5.

The left hand head of the core 2 consists of the metallic disk 6 and theinsulating disk 7. The disk 6 has a central opening 8 the edges of which9, 9 are designed to fit snugly in the groove 10 in the end of the core2. The diameter of the core at the bottom of the groove 10 is preferablyvery slightly larger than the original diameter of the opening 8 in thedisk 6 and the width of the groove 10 is substantially the thickness ofthe disk 6 so that the disk elastically engages the core preferably bothat the sides and bottom of the groove.

On opposite sides of the opening 8 the disk 6 is slotted as at 11 and 12so that the diskis in fact made up of the two halves 13 and 14 connectedtogether at 15 so that the disk can be slightly sprung for the purposeof assembling it on the end of the core 2. The two halves 13 and 14 aresprung apart slightly so as to increase the diameter of the opening 8sufficiently to allow the disk to slip over the end of the core uhtilthe edges 9, 9 fit into the groove 10. When the halves 13 and 14 arereleased the elastic quality of the metal causes the disk to grip thecore in the groove 10 and hold the disk securely in, place. The sidewalls of the groove 10 serve as shoulders to prevent the disk 6 fromdisplacement.

The insulating disk 7 fits on the core 2 just inside of the disk 6 andforms an insulating medium between the metallic disk 6 of the magnet andthe windings. The insulating disks may be cemented to the metallic disksand a suitable'number of holes as 71 pierced near the center line of theslots 12 in the metal disk 6 for the winding terminals. The disk 7 notonly insulates the coil from the metallic disk 6 but closes the openings11 and 12.

Th right hand head of the magnet is similarly made up of the metallicdisk 15 and the insulating disk 16, the disk'15 fitting on to the righthand end of the core 2 in the groove 17 In Fig. 5 I have shown amodification of the metal head. The disk 18'has a central opening 19 andslots 20 and 21 at opposite sides thereof so as to divide the disk intotwo parts connected at 22 and 23. This construction is stifi'er but notquite so easy to assemble on the core as the disk 6.

The disk 6 of Figs. 2 to 4 and disk 24 of Fig. 6 also avoid inducedcurrents as there is no metallic circuit in them around the core.

In Fig. 6 the disk 24 has interiorly directed prongs or tongues 25. InFig. 7 the core 26has recesses 27 for receiving the tongues 25 andproviding in eifect shoulders for pcsitioning the disk 24longitudinallyand circumferentially. q

\Vhen constructed as preferred the disk 6 even when the opening 8 isround grips the core snugly in the groove 10 and is not easily turned. Apart of the core 2 may be indented however or drawn over into the groove10 between the parts 13 and 14 as at 28, F ig, 4 to afford additionalmeansfor preventing the disk 9 from turning on the core.

The slots 11 and 12 afford convenient ingress and egress for the coilterminals.

The advantages of the invention are the cheap'cost of construction, itsdurable char- 'acter and freedom from liability to injury when subjectedto heat or shock and its economy of space and material.

'This applicatlon 1s a divisional applica- "tion from #595,042 filed byme December What Iclaim is 4 1. In an electromagnet, a core for a magnetwinding having a peripheral groove therein and a coil-supporting headdisk rigidly applied to the said core comprising a plate of sheet metalof substantially the same thickness as the width of the grooveway in thecore, provided with a central opening of substantially the size of thegrooved portion of the core whereby to grip the core when appliedthereto and with a slot extending inwardly from the edge portion of theplate into the said central core opening to thereby render said platesufficiently elastic to be forced over the core into enga ement in thegrooveway therein, said slot eing of less width than the diameter of thecore opening in the disk to prevent the disk working off the core.

2. In an electromagnet construction, a core rod of magnetic material, arelatively thin nonmagnetic sheet metal disk permanently and rigidlygripped on one end of said core rod and forming a head for retaining thecoils in place on the core rod, said core rod having a shoulder toprevent endwise movement of said disk, and said head disk being slottedto enable it to be forced on to the end of said rod, magnet coils woundon the core rod and supported in coil form by the metallic head disk andinsulating material between the coils and the head disk.

3. In an electromagnet, a spool construction, comprising a core rod ofmagnetic material having a peripheral groove therein near the endthereof a thin sheet metal end disk having a central opening and rigidlysecured in the groove at the end of the core rod, said sheet metal'diskhaving a slot cut therein from the edge to the central opening to adaptthe end disk to being sprung into place to assemble it on the core rodand to avoid an electric circuit around said disk, a thin insulatingdisk on the core rod covering the inside face of the end disk and a wirecoil wound on the core against the insulating disk supported by themetallic end disk.

4. An electromagnet comprising a core rod of magnetic material,relatively thin nonmagnetic metal head disks applied to the oppositeendportions of the core rod, means rigidly securing said. metalnon-magnetic head disks on the core rod and holding the same thereonagainst endwise displacement, relatively thin disks of insulatingmaterial surrounding the core rod and engaging the inside faces of themetallic non-magnetic head disks, and a magnet coil wound on the corerod between the insulating disks, supported in coil form by the metalhead disks and insulated from said metal supporting disks by theinsulating disks at the inside faces of said supporting disks.

ELISHA W. MCGUIRE, RoB'r. S. ALLYN.

